For some time, known rinse water tank apparatuses such as that set forth in Patent Document 1 (Japanese Patent Unexamined Publication No. 2002-21144) for storing rinse water to flush a toilet have been furnished with a flow regulating cylindrical body disposed to surround the vicinity of a discharge port formed at the bottom portion of the rinse water tank, a float valve (discharge valve) for opening and closing a discharge port disposed on the interior portion of the cylindrical body, and a regulating means (regulating band or the like) capable of regulating the opening surface areas of multiple water passageways formed on the side surface of the cylindrical body.
In conventional discharge valve apparatuses of this type, the amount of rinse water supplied to the toilet can be easily adjusted by regulating the opening surface areas of water passageways in the cylindrical body through manual operation of a regulating means when the float valve releases the discharge port.